| | [這篇文章最後由JuanFe在 2024/11/23 01:55pm 第 3 次編輯]
Cycas multipinnata C. J. Chen & S. Y. Yang, Acta Phytotax. Sin. 32. 239. 1994.多歧苏铁 duo qi su tie {Cycas longipetiolula D. Y. Wang; Epicycas multipinnata (C. J. Chen & S. Y. Yang) de Laubenfels.}
Trunk almost subterranean, to 40 × 20 cm above ground; bark brown-gray, scaly.
Leaves 1(or 2), 3-pinnate, trullate in outline, flat, 3-7 m × 60-100 cm;
petiole subterete, 1.5-2.5 m × 3-6 cm;
spines 30-50 along each side, 3-6 cm apart, compressed conical, 3-5 mm;
primary leaflets in 12-22 pairs, longitudinally inserted at 60-90° to primary rachis, lanceolate, slightly "V"-shaped in cross section at 100-130° to rachis;
middle leaflets largest, 35-60 × 15-20 cm;
basal and apical leaflets gradually shorter, 20-40 × 10-15 cm;
secondary leaflets flabellate or obtriangular, dichotomously (2 or)3-5-forked, 20-22 × 5-15 cm, with petiolule 0.5-5 cm;
segments (ultimate leaflets) obovate-linear, regular, 7-12 × 1-2 cm, papery, midvein slightly elevated on both surfaces, base decurrent, glabrous, margin entire or somewhat wavy, apex shortly acuminate to caudate.
Pollen cones fusiform-cylindric, 15-23 × 4-6 cm;
microsporophylls 1.2-2 cm × 8-10 mm, tomentose, apex acute.
Megasporophylls 8-12 cm, brown tomentose, glabrescent;
stalk ca. 4 cm;
sterile blade triangular-ovate, 4-7 × 3-6.5 cm, deeply divided into 25-35 subulate lobes 1-3.5 cm;
ovules 3-5 on each side of stalk.
Seeds 6-10, greenish to yellowish, obovoid, slightly compressed, 2.5-3.2 × 2.3-2.8 cm;
sclerotesta finely verrucose, apex mucronate.
Pollination Apr-May, seed maturity Oct-Nov.*
Red soil over granite or limestone in somewhat shaded monsoon forests along valleys; 200-1000 m. SE Yunnan (Gejiu Shi, Hekou Yaozu Zizhixian, Mengzi Xian, Pingbian Miaozu Zizhixian)
This and Cycas debaoeusis, with their 3-pinnate leaves, are the most distinct of all extant cycads. Cycas multipinnata is also one of the most endangered cycads in China, mainly as a result of over collection by commercial dealers and habitat damage as forests are opened up for farmland.
If conservation measures are not taken immediately, the species will most likely become extinct in the wild within the next ten years.
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2019/09/15 05:48am 
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